Disposable absorbent pad

ABSTRACT

A disposable absorbent pad comprising of a fibrous material web, folded longitudinally and having marginal portion specially treated to be temporarily moisture impermeable, the folding being made in such a manner that one side of the absorbent pad is moisture absorbent whereas the other side thereof forms a moisture-tight barrier layer, wherein the barrier layer is formed by the both marginal portions of the original material web which portions are each folded first once to form double-layer edge portions and then folded again to be placed one upon the other on a central nonfolded, absorbent portion of the material web.

United States Patent Svensson Oct. 14, 1975 [5 DISPOSABLE ABSORBENT PAD 3,665,923 5/1972 Champaigne, Jr. 12s/290w 75 I t -E S k d, 1 nven or gt E s: vensson stoc Sun Przmary ExammerR1chard A. Gaudet Assistant ExaminerHenry S. Layton Assigneel Siemens Aktiellgesellschafi, Berlin & Attorney, Agent, or Firml-lill, Gross, Simpson, Van

Munich, Germany Santen, Steadman, Chiara & Simpson [22] Filed: May 7, 1974 Appl. No.: 467,658

Foreign Application Priority Data May 8, 1973 Sweden 7306424 References Cited UNITED STATES PATENTS Harmon 128/290 W ABSTRACT A disposable absorbent pad comprising of a fibrous material web, folded longitudinally and having marginal portion specially treated to be temporarily moisture impermeable, the folding being made in such a manner that one side of the absorbent pad is moisture absorbent whereas the other side thereof forms a moisture-tight barrier layer, wherein the barrier layer is formed by the both marginal portions of the original material web which portions are each folded first once to form double-layer edge portions and then folded again to be placed one upon the other on a central nonfolded, absorbent portion of the material web.

5 Claims, 3 Drawing Figures U.S. Patent Oct. 14,1975 3,911,921

Fig, 7

DISPOSABLE ABSORBENT PAD FIELD OF THE INVENTION This invention relates to disposable absorbent pads, particularly adapted to be used as sanitary napkins in connection with menstruation periods or to absorb other secretions.

BACKGROUND OF THE INVENTION A well known disposable sanitary napkin comprises two portions, viz. on one hand an absorbent pad of a fibrous material, sometimes called fluff," in an enclosing envelope of a fibrous material web, normally called .nonwoven, and, on the other hand, a moisture tight portion which is affixed to one side of the absorbent pad and consists of layers of a specially treated, folded web of nonwoven, cellulose tissue or any corresponding material.

The expression specially treated has been used above to include any material manufactured by a known and patented method by which a web of nonwoven, tissue, paper or cellulose is made at least temporarily moisture-tight but which when wetted heavily absorbs liquid to such an extent that the web assumes the consistency of a very soft gel, or even dissolves. For convenience, a material treated in this way will sometimes be referred to as a moisture-tight material of the class described. In one utilization of the just mentioned method one side of a cellulose tissue web is provided with a layer of carboxymethylcellulose, and the layers in question are sometimes called CMC-layers.

The sanitary napkin as described above has been met which much approval in practice. However, it has been found possible in many instances to use a simpler and thus more inexpensive alternative.

BRIEF DESCRIPTION OF THE INVENTION According to the invention there is provided a disposable absorbent pad comprising a fibrous material web which has been folded longitudinally and the marginal portion have been specially treated in such a manner that it is temporarily moisture impermeable at the specially treated portion but is easily moisture permeable at the central portion, the folding being such that one side of the absorbent pad is moisture absorbent whereas the other side thereof forms a moisture-tight barrier layer, and the barrier layer being formed by both marginal portions of the original material web which marginal portions are each centrally folded to form double-layer edge portions, each having a width broadly corresponding to the width of the central, non-folded portion of the material web.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an absorbent pad according to the invention in a first embodiment thereof;

FIG. 2 shows schematically the absorbent pad in FIG. 1 in cross-section along the plane IIII in FIG. 1;

FIG. 3 shows very schematically a similar crosssection of a second embodiment of the absorbent pad according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS In the embodiment of the absorbent pad according to the invention as shown in FIGS. 1 and 2 the pad comprises a fibrous web 10, such as of creped paper of tis- "layer edge portions 11,12, the widths of which are central portion.

about the same as that of central non-folded portion 13 of the web. After, the folding over. the said doublelayer edge portions 11,12 have been folded again to be placed one upon the other on the central portion 13 of the web.

In the present case the edge portions 11 and 12 have been treated with carboxymethylcellulose, CMC, for instance, in such a manner that the CMC-layers of each part of each edge portion will face each other. The mutually facing'CMC-layers of each edge portion form jointly barrier layers 14 and 15, respectively, as indicated by dashed lines in FIG. 2. On its uppermost side, i.e. the side which in use will face away from the body, the absorbent pad is preferably provided with a double sided adhesive tape 16 for affixing the pad to the crotch portion of panties or scanties.

For convenience, in FIG. 2 the web 10 is shown as comprising one layer'only. However, in practice, the web 10 preferably comprising two layers of the same width, of which layers only the uppermost one is treated with CMC along the edge portions thereof.

The central portion 13 of the fibrous web 10 is absorbent, and more particularly entirely satisfactorily absorbent to absorb minimal secretion quantities, such as at the end of menstruation periods or other minimal secretion quantities. The barrier layers 14 and 15 afford an adequate security against liquid penetration to the front side or outer side of the absorbent pad.

The embodiment as shown in FIG. 3 is similar to the one in FIG. 2 but in this second embodiment the absorbent pad is provided with an absorbent filling l7, preferably resting on a cellulose tissue web 18 or the like. As is known per se the absorbent filling 17 may have longitudinal compression lines to improve the spreading properties. Also, the filling 17 may have a varying thickness, longitudinally and/or transversely of the absorbent pad, so that the maximum amount of filling material 17 is present in the area where the absorption should be greatest. It is also possible to mix a filling 17 of so called fluffed cellulose with e.g. rayon fibers or with e.g. rayon fibers with various other additions so as to improve the absorption or spreading or e.g. to make the filling l7v bactericidal.

What I claim is:

1. A disposable absorbent pad, comprising:

a web of absorbent fibrous material, there being a central portion, and a pair of 2-section marginal portions respectively secured by a longitudinal fold integrally with said central portion and both disposed in overlying relation to one side of said central portion, each of said marginal portions having had a special treatment so as to be temporarily moisture impermeable, each marginal portion being substantially twice the width of said central portion and having a central longitudinal fold between its sections whereby each said marginal portion twice overlies said central portion.

2. A disposable absorbent pad according to claim 1 in which that section of each said marginal portion which has the edge of the web underlies the section of the marginal portion lying more remotely from said 3. A disposable absorbent pad according to claim 1 including a second web of absorbent fibrous material 3 4 disposed coextensively against said first-named web, 'four marginal sections and said central portion. and also having a pair of Z-section marginal portions 5. A disposable absorbent pad according to claim 4 but which are devoid of said special treatment. including a layer of cellulose tissue between said cen- 4. A disposable absorbent pad according to claim 1 tral portion and said filling.

including an absorbent filling disposed between the 5 UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,911,921

DATED October 14, 1975 |NVENTOR(S) Jan-Eric Svensson it is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the face sheet of the patent, the name of the assignee appears --Siemens Aktiengesellschaft, Berlin 81 Munich, Germany-- and it should appear as --Aktieb0laget Stille-Werner, Stockholm, Sweden--.

Signed and Scaled this twenty-fourth Day Of February 1976 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Alluring Offic Commissioner oj'Parents and Trademarks 

1. A disposable absorbent pad, comprising: a web of absorbent fibrous material, there being a central portion, and a pair of 2-section marginal portions respectively secured by a longitudinal fold integrally with said central portion and both disposed in overlying relation to one side of said central portion, each of said marginal portions having had a special treatment so as to be temporarily moisture impermeable, each marginal portion being substantially twice the width of said central portion and having a central longitudinal fold between its sections whereby each said marginal portion twice overlies said central portion.
 2. A disposable absorbent pad according to claim 1 in which that section of each said marginal portion which has the edge of the web underlies the section of the marginal portion lying more remotely from said central portion.
 3. A disposable absorbent pad according to claim 1 including a second web of absorbent fibrous material disposed coextensively against said first-named web, and also having a pair of 2-section marginal portions but which are devoid of said special treatment.
 4. A disposable absorbent pad according to claim 1 including an absorbent filling disposed between the four marginal sections and said central portion.
 5. A disposable absorbent pad according to claim 4 including a layer of cellulose tissue between said central portion and said filling. 